A well-detailed introduction on what is a learning management system (LMS) and the benefits that an LMS platform can offer to your employees, students and customers.
Even though your shower grout looks dry, using it too early or sealing it before it's ready may damage it, leading to premature failure. Most cement-based grouts require a cure time of 48 to 72 hours before applying a penetrating sealer. After sealing, wait a minimum of 24 hours before using the shower; some products may recommend three days instead. Other grout formulas may require a shorter or longer drying time, and epoxy-based grouts may allow you to skip the sealer, thus the wait time before using your shower or bathtub.
Roughly speaking, 30 days. Honestly, it would be best to wait that long to seal it. However, most people - and for good reason - don't want to wait that long. It's too easy for there to be something spilled on it. If you really want to do a bang-up job, do your first application of sealant after 48 hours. Then, 30 days later, clean the grout with a toothbrush, using a strong mix of bleach & water.